Authors:Brigitta Török, Adél Len, and Zoltán Orbán
This paper presents a nonstandard experimental procedure for detection of the presence of salts in building materials. The proposed tests helped modeling the deterioration of specific historical building materials caused by salts. The specimens were subject to visual survey and scanning electron microscope analyses, after submerging them in salt solutions. The results showed the damage of brick, cement based mortar and lime based mortar, caused by various concentrations of sulphate and chloride solutions. By this method various types of salt crystals could be identified. In cement and lime based mortars larger extents of salt deposits were found. A relevant difference between the control samples and the salt treated samples was observed.
Authors:A. Duran, L. Perez-Maqueda, J. Poyato, and J. Perez-Rodriguez
Roman ancient mortars have been widely studied, in connection with both diagnosis and application required for restoring.
Thermoanalytical experiments performed on mortars from Pompeii and Herculaneum provided a very good understanding of the technology
employed. The mortars from Pompeii were obtained by the proper mixing of lime and marble grains while mortars of Herculaneum
by lime and silicates compounds. The position of the endothermic peak of calcite decomposition showed important variations
in the different samples studied, which was assigned to the different crystallinity and particle sizes. Experiments under
CO2 flow confirmed the presence of magnesium calcium carbonates.
The properties of hydraulic mortars were studied by means of simultaneous thermal analysis (STA), according to a procedure
proposed in the literature. Hydraulic limes, cement and/or slaked lime were mixed using different proportions of both inert
and reactive aggregates, in order to test the effectiveness of such procedure in distinguishing the different degree of hydraulicity
of such samples. The use of the normalized coordinates suggested in the literature results in overlapping of the clusters
of different kinds of mortars. Modified coordinates are proposed, which give promising results in view of outlining a ‘master
curve’ of hydraulicity.
Authors:L. Baraniak, M. Thieme, G. Bernhard, and H. Nitsche
With the background of uranium mine restoration the adsorption of radium on different kinds of sandstone, claystone and lime
marl was studied as a function of such parameters as water composition, acidity, phase contact time and the concentration
of radium, barium and sulfate by static butch experiments at the mine temperature of 14 °C.
DTA/TG/DTG thermoanalytical investigation and X-ray diffractometry were carried out on hydraulic lime pastes obtained by mixtures
of thermally activated red earth with lime. Hydration reactions proceed properly mostly due to the high silica and alumina
content. In a long period of curing the paste presents calcium silicates hydrate in high quantities while there are moderate
quantities of calcium monocarboaluminate hydrate, ettringite and gehelenite hydrated. In presence of chloride, pastes lead,
after few days, a sensible acceleration of the hydration with the formation of calcium silicate hydrate and calcium chloroaluminate
hydrate. The total amount of neo-formed hydrate products in the hardened paste, indicate a development of the solidifying/stabilizing
capacity of the hydraulic binder.
Authors:Brigitta Tóth, Dr. Szilvia Veres, Nóra Bákonyi, Éva Gajdos, Marianna Marozsán, and Dr. László Lévai
Környezetünk védelme közös feladat. Minden szennyezés, ami földjeinket, növényeinket, a szűkebb, vagy a tágabb értelemben vett környezetünket éri, előbb-utóbb megjelenik az élelmiszerlánc valamelyik tagjában, végül a piramis csúcsán álló emberben.
Munkánk célja egy átlátható képet adni néhány ipari hulladék – cementpor, mészpor, mészhidrátpor – növényekre gyakorolt fiziológiai hatásáról. A vizsgált anyagok a növények számára sok létfontosságú elemet tartalmaznak (pl.: vas, kálium, magnézium, foszfor, cink), de mindezek mellett alumínium, ólom, króm és kobalt is megtalálható bennük. Ezek figyelembevételével vizsgáltuk a csírázásra gyakorolt hatást, a növények elemfelvételét, a száraz anyag felhalmozást és a relatív klorofill tartalmat. A laboratóriumi kísérletek során bizonyítottá vált a cementpor, a mészpor és a mészhidrátpor kedvező és kedvezőtlen fiziológiai hatása. Kétségtelen, hogy a laboratóriumban a környezet kompenzáló hatása kizárt, azonban a környezeti terhelések semlegesítése természetes körülmények között sem végtelen.
Authors:M. Franquelo, M. Robador, V. Ramírez-Valle, A. Durán, M. Jiménez de Haro, and J. Pérez-Rodríguez
Roman ceramics of two hydraulic mortars used to build the pond and water channel of Mithraeum house from Mérida (Spain) have
been studied. The sizes of the ceramic fragments found were different in both of the samples studied, showing different behaviour
in the reactions with the lime. The X-ray diffraction of the ceramic shows the presence of quartz, mica (biotite), anorthite
and hematite accompanied by amorphous phase, being observed scarce vitrification. The presence of mica confirms a firing temperature
for manufacturing the ceramic below 900°C. In one of the ceramics studied, X-ray diffraction did not show calcite. However,
in the FTIR appear bands that could be assigned to carbonates absorptions and likewise, carbonates were identified in the
DTA-TG curves. Ca and small quantities of Si and Al were also identified by SEM-EDX on the surface of the pores that could
be due to an amorphous phase formed in the reaction of lime with the Si and Al of the ceramic. On the other hand, in other
ceramic samples carbonates (about 10%) were detected. The carbonates have been found filling the pores, sometimes accompanied
by a new calcium-aluminium-silicate phase produced by the reaction between the lime and the amorphous phase of the ceramic.
The carbonates and the new phases formed inside the pores are responsible for the decrease of the porosity and for the formation
of new phases during the heating of the ceramics.
In this research kinetic analysis of the Tuncbilek lignite and its mixture with different binders (molasses, CMC, sulphide
liquor, heavy crude oil, sodium silicate,cornstarch, lime, peridur, bentonite, cement and poly(vinyl-acetate)) were analysed
by thermogravimetric (TG/DTG) methods. Two different kinetic models (Arrhenius and Coats–Redfern) were used to determine the
activation energies of the samples studied. The concept of weighed mean activation energy was applied to determine the overall
reactivity of the samples. It was observed that molasses, CMC, heavy crude oil, peridur, bentonite and poly(acetate) decreased
the activation energy of the coal sample, whereas, all other binders increased the activation energy of the coal sample.
A simple device suitable for continuous monitoring of carbon dioxide evolved during thermal decomposition reactions is described.
Carbon dioxide is transported by a carrier gas through the device connected to thermoanalytical equipment and absorbed by
soda lime reagent. The reaction heat released is linearly proportional to the amount of carbon dioxide absorbed.